Such telescopic masts, which are primarily intended for temporary use, have a very wide range of use. They are used, inter alia, as aerial masts by the armed forces, by Telecommunications Administrations, and by Television Companies. They are also used as standards for electric lighting equipment, measuring and control equipment, and the like. Consequently, it must be possible to transport and erect the masts in a relatively easy fashion.
Most of the masts used today need to be guyed or otherwise stiffened when erected, which renders it more difficult to erect the mast and greatly extends the time required herefor. The lines of known masts lie outside the mast and are hence unprotected and liable to be damaged by the rough treatment to which such masts are subjected. In addition hereto, the unprotected, externally located lines are also liable to pick-up dirt and other foreign matter and to carry the same into the mast interior, which can readily impair the telescopic function of the mast. Furthermore, the type of mast most used today includes a plurality of separate lines, which, among other things, makes line changes extremely expensive, since such changes make it necessary to dismantle the mast sections completely.
Another disadvantage with most of the known masts is that the mast sections are not lifted from the centre of the mast, and hence the sections are liable to jam and become stuck.